1. Field of the Invention
Exemplary embodiments of the present invention relate to a liquid crystal display.
2. Discussion of the Background
A liquid crystal display is currently one of the most widely used flat panel displays. The liquid crystal display includes two display panels on which field generating electrodes such as a pixel electrode and a common electrode are formed and a liquid crystal layer that is disposed therebetween. An image is shown on the liquid crystal display by applying voltage to a field generating electrode to generate an electric field in a liquid crystal layer, which determines alignment of liquid crystal molecules of the liquid crystal layer and controls polarization of incident light.
The liquid crystal display includes a switching element that is connected to each pixel electrode, and a plurality of signal lines such as a gate line and a data line for applying voltage to a pixel electrode by controlling the switching element.
The liquid crystal display receives an input image signal from an external graphic controller. The input image signal includes luminance information of each pixel, and each luminance has a predetermined value. Each pixel receives a data voltage that corresponds to desired luminance information. The data voltage that is applied to the pixel is represented by the pixel voltage according to a difference in relative voltage, and each pixel shows luminance illustrating a gray level of an image signal according to the pixel voltage. At this time, the pixel voltage range that can be used by the liquid crystal display is determined according to a driving unit.
Meanwhile, in order to apply a data voltage to each pixel electrode of the liquid crystal display, each pixel electrode is connected to a switching element, and since light does not penetrate through a position at which the switching element is formed, as the number of switching elements is increased, the aperture ratio of the liquid crystal display decreases. In addition, in order to connect various signal transfer lines that are formed on different layers to transfer signals to each pixel, a contact hole is formed, and light does not penetrate through a region in which the contact hole is formed, such that the aperture ratio of the liquid crystal display is lowered.
Meanwhile, as the length of the signal line for transferring the signal to each pixel electrode of the liquid crystal display is increased, resistance increases, such that a signal delay occurs, thereby lowering a display quality.
Meanwhile, the driving unit of the liquid crystal display is attached to the display panel by directly mounting it in a form of a plurality of integrated circuit (IC) chips on the display panel or mounting it on a flexible circuit layer, and the IC chip accounts for a high percentage of the manufacturing cost when manufacturing the liquid crystal display. Particularly, as the number of data lines to which data voltage is applied increases, the cost of the driving unit of the liquid crystal display increases.
In addition, in order to increase a display quality of the liquid crystal display, it is necessary to implement a liquid crystal display that has a high contrast ratio, an excellent light viewing angle, and a rapid response speed.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that is not prior art.